RF architecture utilizing a MIMO chipset for near field proximity sensing and communication

Abstract

A re-configurable RF architecture includes both a 2×2 MIMO mode and a 1×2 MIMO mode The 2×2 MIMO mode includes a first RF chain coupled with a first dual band antenna and configured to both transmit (Tx) and receive (Rx) using two different RF protocols. The 2×2 MIMO mode also includes a second RF chain coupled with a second dual band antenna and configured to both Tx and Rx using a single RF protocol. The first RF chain may be coupled with a third antenna configured for near field proximity sensing. The RF architecture is reversibly switchable from the 2×2 MIMO mode to the 1×2 MIMO mode when near field proximity detection is required. In the 1×2 MIMO mode the Tx/Rx capabilities of the second chain using the second dual band antenna are retained and the first chain is configured for Rx only capability using the third antenna.

What is claimed is: 
     
       1. An integrated circuit (IC), comprising:
 radio frequency (RF) circuitry configured to implement a 2×2 Multiple-Input/Multiple-Output (MIMO) mode and a 1×2 MIMO mode, the RF circuitry configured to reversibly switch between the 2×2 MIMO mode and the 1×2 MIMO mode in response to a mode signal electrically coupled with a RF switch, the RF circuitry including 
 a first RF chain electrically coupled with the RF switch and configured, when the mode signal is set to the 2×2 MIMO mode, to be electrically coupled through the RF switch with a first dual band antenna and to transmit and receive, using the first dual band antenna, first and second dual band RF signals, and 
 the first RF chain configured, when the mode signal is set to the 1×2 MIMO mode, to be electrically coupled through the RF switch with a near field proximity detection antenna, and to receive only, using the near field proximity detection antenna, a fifth RF signal, and 
 a second RF chain electrically coupled with a second dual band antenna and configured to transmit and receive third and fourth dual band RF signals in the 1×2 or 2×2 MIMO modes. 
 
     
     
       2. The IC of  claim 1 , wherein a selected one or more of the first, second, third or fourth dual RF band signals comprise WiFi signals. 
     
     
       3. The IC of  claim 1 , wherein the third or fourth dual band RF signals comprises a Bluetooth (BT) signal. 
     
     
       4. The IC of  claim 1 , wherein a selected one or more of the first, second, third or fourth dual RF band signals comprises an Ad Hoc (AH) WiFi signal. 
     
     
       5. The IC of  claim 1 , wherein the first and second dual band antennas are monolithically integrated on a same semiconductor die as the RF circuitry. 
     
     
       6. The IC of  claim 5 , wherein the first and second dual band antennas are positioned at opposite corners of the die. 
     
     
       7. The IC of  claim 1 , wherein the near field proximity detection antenna is external to the RF circuitry and is electrically coupled with the RF circuitry. 
     
     
       8. The IC of  claim 1 , wherein the RF circuitry is configured to measure relative signal strength of the fifth RF signal using received signal strength indicator (RSSI) measurement. 
     
     
       9. The IC of  claim 8 , wherein when the RSSI measurement exceeds a threshold value, the RF system generates a signal indicative of a RF transmitting device being in direct contact with, in near field proximity to, or in very close near field proximity to the near field proximity detection antenna. 
     
     
       10. The IC of  claim 1 , wherein the near field proximity detection antenna comprises a substrate of an electrically conductive material including a plurality of separate apertures formed in the substrate, one or more of the separate apertures comprise passive slits that are electrically decoupled from the RF switch, and another one or more of the separate apertures comprises an antenna having a length edge electrically coupled with the RF switch and an opposing length edge electrically coupled with a ground potential. 
     
     
       11. The IC of  claim 10 , wherein the antenna comprises a slot antenna. 
     
     
       12. The IC of  claim 10 , wherein the antenna includes dimensions configured to detune the antenna below a frequency of a selected one or more of the first, second, third, or fourth dual band RF signals. 
     
     
       13. The IC of  claim 10 , wherein the first dual band antenna, the second dual band antenna, or both are configured to transmit and receive RF signals at two different RF frequencies comprising 2.4 GHz and 5 GHz. 
     
     
       14. A method for multiple dual band wireless communication and wireless near field proximity detection, comprising:
 setting a state of a mode signal in a radio frequency (RF) system including circuitry for a 2×2 Multiple-Input/Multiple-Output (MIMO) mode and a 1×2 MIMO mode; 
 coupling, when the mode signal is set to the 2×2 MIMO mode, a first RF chain of the RF system with a first dual band antenna configured to transmit and receive first and second dual band RF signals; 
 coupling, when the mode signal is set to the 2×2 MIMO mode or the 1×2 MIMO mode, a second RF chain of the RF system with a second dual band antenna configured to transmit and receive third and fourth dual band RF signals; and 
 coupling, when the mode signal is set to the 1×2 MIMO mode, the first RF chain with a near field proximity detection antenna, the first RF chain configured to only receive a fifth RF signal from the near field proximity detection antenna when the 1×2 MIMO mode is set. 
 
     
     
       15. The method of  claim 14 , wherein the near field proximity detection antenna comprises a detuned slot antenna. 
     
     
       16. The method of  claim 14 , wherein the near field proximity detection antenna comprises a substrate of an electrically conductive material including a plurality of separate apertures formed in the substrate, one or more of the separate apertures comprise passive slits that are electrically decoupled from the RF switch, and another one or more of the separate apertures comprises an antenna having a length edge electrically coupled with the RF switch and an opposing length edge electrically coupled with a ground potential. 
     
     
       17. A multi-channel dual band wireless communication and wireless near field proximity detection system, comprising:
 circuitry configured to implement a 2×2 Multiple-Input/Multiple-Output (MIMO) mode and a 1×2 MIMO mode, the circuitry configured to reversibly switch between the 2×2 MIMO mode and the 1×2 MIMO mode in response to a mode signal electrically coupled with a RF switch, the circuitry including 
 a first RF chain electrically coupled with the RF switch and configured, when the mode signal is set to the 2×2 MIMO mode, to be electrically coupled through the RF switch with a first dual band antenna and to transmit and receive first and second dual band RF signals using the first dual band antenna, and 
 configured, when the mode signal is set to the 1×2 MIMO mode, to be electrically coupled through the RF switch with a near field proximity detection antenna and to receive only, using the near field proximity detection antenna, a fifth RF signal, and 
 a second RF chain electrically coupled with a second dual band antenna and configured, when the mode signal is set to the 2×2 MIMO mode or the 1×2 MIMO mode, to transmit and receive third and fourth dual band RF signals using the first dual band antenna. 
 
     
     
       18. The system of  claim 17 , wherein the near field proximity detection antenna comprises a substrate of an electrically conductive material including a plurality of separate apertures formed in the substrate, one or more of the separate apertures comprise passive slits that are electrically decoupled from the RF switch, and another one or more of the separate apertures comprises an antenna having a length edge electrically coupled with the RF switch and an opposing length edge electrically coupled with a ground potential. 
     
     
       19. The system of  claim 18 , wherein the antenna includes dimensions configured to detune the antenna below a target frequency. 
     
     
       20. The system of  claim 17 , wherein the near field proximity detection antenna is configured to generate the second RF signal in response to an external wireless device that transmits a fifth RF signal and is placed directly on, in near field proximity to, or in very close near field proximity to the near field proximity detection antenna.